Screw cap with a cutting sleeve

ABSTRACT

For the first time, a screw cap ( 1 ) is realized with which a tubular bag to which the screw cap ( 1 ) is attached can be opened by a self-cutting process and metered dispensing from a metering opening ( 31 ) is simultaneously realized. The screw cap ( 1 ) consists of a lower part ( 2 ), on which a spacing means ( 4 ), used in practical terms as transport protection, is placed, and onto which a cutting sleeve ( 3 ) with a lateral metering opening ( 31 ) is screwed. The container can be opened by means of the cutting sleeve ( 3 ) and thereafter its contents can be dispensed in a metered manner by means of a valve piston ( 5 ) that is guided in the cutting sleeve ( 3 ) by a screwing movement. In the closed state, the valve piston ( 5 ) reaches into the cylinder ( 30 ) of the cutting sleeve ( 3 ) underneath the metering opening ( 31 ) and seals the cylinder ( 30 ), which is open at both ends, off against the container that is welded to the flange ( 21 ) of the lower part ( 2 ).

BACKGROUND OF THE INVENTION

The present invention relates to a screw cap, consisting of a lower part, which comprises a cylindrical threaded tubular section and a terminal flange for attaching to a closed container made from film material, and a cutting sleeve connected to the thread of the lower part by means of a threaded connection.

Screw caps of the kind mentioned above have already been known since the late 1980s. For example, the European patent application EP 0328652 discloses such a cap. Further modifications thereto are disclosed, for example, by the U.S. Pat. No. 5,147,070, the WIPO patent application 99/62776, the WIPO patent application 2004/083055 and many others. Closures of this kind use entraining elements to drive the cutting sleeve, said elements being mounted to the bottom of the top surface of the screw cap. If said screw cap is unscrewed, the cutting sleeve moves simultaneously in a rotary motion which is in the same direction but has opposite axial displacement. In so doing, the cutting sleeve cuts open the closed container, wherein a combined perforating and cutting effect is employed.

Closures of this kind have established themselves in the market and have become an integral part of closed receptacles made from film material. Said receptacles have been to date substantially manufactured from laminated film material which consists of a combination of plastic films, cardboard layers, an aluminum barrier layer and an inner sealing layer made from plastic film. Receptacles consisting of such multi-layer film material are relatively pressure-resistant and have been to date a main stay on the beverage market.

Receptacles have only recently been manufactured from pure plastic film material, said receptacles being substantially more flexible and correspondingly sensitive to pressure. For that reason, not only beverages can now be packaged in such receptacles but also highly viscous liquids, thixotropic liquids or pourable solids. Such contents can in fact be dispensed in a metered manner by pressure being exerted on the receptacle when the closure is open and in so doing reducing the interior volume. A controlled, metered dispensing is, however, difficult to achieve. In particular if the receptacle is still practically completely full, the user has to lift the same. In so doing, a more or less strong pressure is automatically exerted on said receptacle depending on the weight of the filled receptacle. Because the screw cap is completely screwed off with the screw closures comprising a cutting sleeve known to date, the complete passageway in the cutting sleeve is open and the chance is extremely great that the liquid spills out merely by lifting the receptacle.

A plurality of the most different shapes of metering closures is also available on the market. Said metering closures have metering openings, wherein the metering opening can correspondingly be opened or closed in a more or less strong manner or even wherein the feed to the metering opening can more or less be opened with, for example, a valve piston.

SUMMARY OF THE INVENTION

Screw caps of the kind mentioned above, which have a cutting sleeve with which the container, on which the screw closure is mounted, can be severed and thereby opened, have not been provided up until now with a metering closure. It is now the aim of the present invention to remedy this situation.

This aim is met by a screw cap of the kind mentioned at the beginning of the application, in which screw cap the cutting sleeve protrudes beyond the lower part and a lateral metering opening as well as an internal thread, in which a valve piston is situated that closes and opens the lateral metering opening, is located in the region where the cutting sleeve protrudes beyond the lower part. In so doing, the valve piston engages in a sealing manner into the cutting sleeve in the region below the lateral metering opening.

Such a screw cap is preferably embodied such that the cutting sleeve is designed to have double walls below the lateral metering opening, comprising an unthreaded inner lateral wall having a terminal cutting edge and an outer lateral wall having internal thread which mesh with the thread on the lower part, and such that the outer lateral wall is shorter in an axial direction than the height of the cylindrical tubular section of the lower part. In this way, the cutting sleeve can now be grasped from the outside and actuated by hand independently of the screwing movement of a screw cap. Whereas the container can thus be opened while the screw cap is still closed, the danger does not exist that liquid is already squeezed out of the container during opening.

Further advantageous embodiments of the subject matter of the invention emerge from the additional dependent patent claims and their importance and mode of operation is explained in the description with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred exemplary embodiment of the subject matter of the invention is depicted in the drawings. In the drawings:

FIG. 1 shows the inventive screw cap in a perspective view prior to the initial use thereof.

FIG. 2 shows the same screw cap in a perspective exploded view, whereas

FIG. 3 shows the screw cap pursuant to FIG. 1 in a diametric vertical section after the actuation of the cutting sleeve in a closed state and

FIG. 4 shows the same view of the screw cap in the maximally opened position.

DETAILED DESCRIPTION

The self-opening screw cap is denoted in its entirety with the reference numeral 1. The same screw cap could however be just as well referred to as a metering closure because the invention relates to a combination of a self-opening screw cap and a metering closure. The inventive screw cap consists of four components, namely a lower part 2, a cutting sleeve 3, a spacing means 4 and a valve piston 5 which is designed as a rotary handle in the uppermost region, wherein only this part is visible in the assembled state. The screw cap of interest here is, as previously mentioned, mounted on a closed container made of film. To this end, the lower part 2 comprises an outwardly protruding, circumferential flange 21. The cutting sleeve 3 has a lateral metering opening 31, which in this case is implemented relatively large as a square window. Prior to initial use, the spacing means 4 is still present, which can be embodied either as a spacing ring or as a tamperproof strip 40. On the one hand, the terminal top surface 52 and on the other hand the circumferential apron 53 which engages over the cutting sleeve in the upper region can be seen here as parts of the valve piston. Said apron 53 serves as a gripping surface and is accordingly provided with ribbing 54.

The individual parts of said screw cap will now be described below in detail with reference to FIG. 2.

The lower part 2 comprises a tubular section 20 at the bottom of which a flange 21 oriented radially outwards is integrally formed in a terminal position. An external thread 22 is applied to the outside of the tubular section 20. The lower part 2 can be adhesively bonded or welded to the closed container. If the closed container relates particularly to a tubular bag made from plastic film, the lower part 2 is preferably welded to said tubular bag. This usually takes place by means of ultrasonic welding. A spacing means 4 can now be placed over the tubular section 20 of the lower part 2, said spacing means 4 approximately bridging the distance between the flange 21 and the external thread 22. In the example depicted here, the spacing means 4 is a spacing ring which can be pushed over the external thread with a slight amount of elongation. Prior to the initial opening of the container, said spacing ring 40 must be removed. To this end, a pull-off tab 41 is integrally formed to said spacing ring 40.

The next step entails unscrewing the cutting sleeve 3. The cutting sleeve 3 consists of a cylinder 30 which is open at both ends and comprises a lateral metering opening 31. The region above the metering opening 31 is referred to here as the valve cylinder region. The cutting sleeve 3 is double-walled below the metering opening 31. This double-walled region is denoted with the reference numeral 33. The inner lateral wall, which cannot be seen here, represents the linear continuation of the valve cylinder region 32. Said inner lateral wall 35 has cutting means 38 at the lower end, by means of which the closed container, on which the screw cap is mounted, can be cut open. Prior to the initial use of the screw cap, said cutting means 38 lie completely within the region of the tubular section 20 of the lower part 2. The outer lateral wall 34 of the double-walled region 33 can particularly be recognized in FIG. 2. This outer lateral wall 34 runs concentrically about the inner lateral wall 35. Said outer lateral wall 34 has an internal thread 36, which cannot be seen in this figure and which matches the external thread 22 of the lower part 2. The spacing ring 40 ensures that the cutting means 38 do not inadvertently come into contact with the container prior to the initial use. Only if this spacing ring 40 has been removed, is the cutting sleeve 3 able to move downwards by means of a screwing movement and thereby open the still closed container. To this end, the cutting sleeve 3 is rotated downwards in a clockwise direction. The double-walled region serves thereby as the gripping surface.

In FIG. 2, the internal thread in the valve cylinder region 32 can likewise not be seen.

The valve piston 5 is embodied as a hollow cylinder 55 and has an external thread 56 on the upper end thereof, which matches the internal thread 39 of the cutting sleeve. The hollow cylinder 55 of the valve piston 5 has a circumferential stop lip 51 which ensures that the valve piston 5 cannot be completely screwed out of the cutting sleeve 3. In the maximally open position, said circumferential stop lip 51 strikes against the upper edge of the lateral metering opening. In addition, a circumferential groove can be located at the same height in the cutting sleeve 3, in which the stop lip engages in the uppermost position.

The function of the inventive screw cap will now be explained once again with reference to FIGS. 3 and 4. After the screw cap has now been assembled in the order depicted in the exploded view pursuant to FIG. 2, the assembled screw cap is welded to the film of a tubular bag by means of a sonotrode which bears on the flange 21. Prior to the initial opening of the container, the spacing means 4 is first removed and the user then grips the outer lateral wall 34 and screws the cutting sleeve 3 downwards until the outer lateral wall 34 rests against the flange 21. In the process, the cutting means 38 is screwed downwards, pierces the film of the container and cuts a rondelle out of said film except for a residual area, said rondelle being simultaneously displaced to the side. A cam-like, outwardly protruding locking means 23 can be provided below the thread. At the same time, a retaining lug 34′ projecting to the inside can additionally be integrally formed on the lower edge of the outer lateral wall 34. The retaining lug 34′ engages below this cam-like locking means 23 and thereby secures this relative position of the cutting sleeve 3 relative to the lower part 2 after the initial use. This position depicted in FIG. 3 now forms the closed use position. The hollow cylinder 55 of the valve piston 5 now projects into the region of the cylinder 30, which is open at both ends, below the metering opening 31. At the same time, a circumferential sealing bead 37 presses in a sealing manner against the lowermost region of the hollow cylinder 55.

The user can now grasp the gripping area of the apron 53 and rotate the valve piston 5 upwards. In so doing, the external thread 56 on the hollow cylinder 55 runs in the internal thread 39 of the cutting sleeve 3 above the metering opening 31. Below said internal thread 39 but above the metering opening 31, a circumferential sealing bead 60 oriented to the inside is mounted to the cutting sleeve 3. The valve piston 5 can be rotated upwards to such an extent that the circumferential stop lip 51 comes to rest on the upper edge of the metering opening 31. In the example depicted here, a closed formed-out area 61 is also provided diametrically opposite the metering opening 31. Said closed formed-out area 61 is formed by the outer lateral wall 34, which is extended in an axial direction and on which, at the height of the upper edge of the metering opening 31, the connection of said outer lateral wall to the upper region of the cylinder 30, which is open at both ends, is established by a shoulder 62 oriented to the inside.

Instead of the closed formed-out area 61, the outer lateral wall 34 can also be generally and circumferentially drawn up to the specified shoulder 62, which runs at the height of the upper edge of the metering opening. This is however not suitable in this case because during closing, a residual volume would be present below said shoulder 62, from which a still considerable residual quantity of the contents would subsequently flow after closing. Such a subsequent flow of the contents cannot take place with the closed formed-out area 61 selected here. The preferred embodiment depicted here comprising the closed configuration diametrically opposite the metering opening 31 can also be realized by means of injection molding with a single lateral slider. 

1. A screw cap (1), consisting of a lower part (2), which comprises a cylindrical tubular section (20) having threads (22) and a terminal flange (21) for attaching to a closed container made from film material, and a cutting sleeve (3) connected to the threads (22) of the lower part (2) by means of a threaded connection, characterized in that the cutting sleeve (3) protrudes beyond the lower part (2) and a lateral metering opening (31) as well as an internal thread (39), in which a valve piston (5) is situated that closes and opens the lateral metering opening (31), is located in the region where the cutting sleeve (3) protrudes beyond the lower part (2), said valve piston engaging in a sealing manner in the cutting sleeve (3) in a region beneath the lateral metering opening (31).
 2. The screw cap (1) according to claim 1, characterized in that the cutting sleeve (3) has double walls (33) beneath the lateral metering opening (31), said double walls (33) comprising an unthreaded inner lateral wall (35) having a terminal cutting edge as cutting means (38) and an outer lateral wall (34) having an internal thread (36) which meshes with the threads (22) on the lower part (2), and in that the outer lateral wall (34) is shorter in an axial direction than a height of the cylindrical tubular section (20) of the lower part (2).
 3. The screw cap (1) according to claim 2, characterized in that a spacing means (4) is mounted prior to the initial use between the flange (21) of the lower part (2) and a lower edge of the outer lateral wall (34) of a region of the double-walled (33) of the cutting sleeve (3).
 4. The screw cap (1) according to claim 3, characterized in that the spacing means (4) is an open or closed spacing ring (40) which rests against the lower part (2).
 5. The screw cap (1) according to claim 3, characterized in that the spacing means (4) is a tamperproof strip (40), which is connected via predetermined breaking point bridges to the outer lateral wall (34) of the double-walled region (33) of the cutting sleeve (3).
 6. The screw cap (1) according to claim 1, characterized in that the valve piston (5) is a hollow cylinder (55), which is closed by a terminal top surface (52) and is provided with a circumferential apron (53) that serves as a gripping surface.
 7. The screw cap (1) according to claim 1, characterized in that stop means (51) are integrally formed on the valve piston (5), said stop means delimiting an opening region of the valve piston (5).
 8. The screw cap (1) according to claim 1, characterized in that at least one circumferential sealing bead (37) is located in the cutting sleeve (3) at least approximately at a height of the lower edge of the metering opening (31).
 9. The screw cap (1) according to claim 1, characterized in that barbs (34′) oriented radially to an inside are integrally formed on a lower edge of an outer lateral wall (34) of the cutting sleeve (3), said barbs being capable of directly or indirectly hooking into the lower part (2) in an assembled state after initial opening.
 10. The screw cap (1) according to claim 6, characterized in that the hollow cylinder (55) of the valve piston (5) has an external thread (56) which meshes with an internal thread of the cutting sleeve (36).
 11. The screw cap (1) according to claim 1, characterized in that a circumferential sealing lip or sealing bead is integrally formed on a lower edge of the valve piston (5).
 12. The screw cap (1) according to claim 7, characterized in that the stop means includes a stop lip (51) disposed in such a way that said stop lip (51) strikes against an inner upper edge of the metering opening (31) at an uppermost position of the valve piston (5).
 13. The screw cap (1) according to claim 12, characterized in that a closed formed-out area (61) which is diametrically opposite the metering opening (31) and corresponds in shape and size to said metering opening (31) is integrally formed on the cutting sleeve (3).
 14. The screw cap (1) according to claim 13, characterized in that two stop means (51) which are diametrically opposed to each other are located on the valve piston (5) and one stop means (51) comes to rest on the inner upper edge of the lateral metering opening (31) and an other stop means comes to rest on an upper inside edge of the formed-out area (61) in the uppermost opening position.
 15. The screw cap (1) according to claim 1, characterized in that a closed formed-out area (61) which is diametrically opposite the metering opening (31) and corresponds in shape and size to said metering opening (31) is integrally formed on the cutting sleeve (3). 